Department of Electrical Engineering.
Nano Lett. 2010 Dec 8;10(12):4813-8. doi: 10.1021/nl102239q. Epub 2010 Nov 12.
Tunnel field-effect transistors were fabricated from axially doped silicon nanowire p-n junctions grown via the vapor-liquid-solid method. Following dry thermal oxidation to form a gate dielectric shell, the nanowires have a p-n-n(+) doping profile with an abrupt n-n(+) junction, which was revealed by scanning capacitance microscopy. The lightly doped n-segment can be inverted to p(+) by modulating the top gate bias, thus forming an abrupt gated p(+)-n(+) junction. A band-to-band tunneling current flows through the electrostatically doped p(+)-n(+) junction when it is reverse biased. Current-voltage measurements performed from 375 down to 4.2 K show two different regimes of tunneling current at high and low temperatures, indicating that there are both direct band-to-band and trap-assisted tunneling paths.
隧穿场效应晶体管由轴向掺杂硅纳米线 p-n 结通过汽液固法生长而成。在进行干法热氧化以形成栅介质壳之后，纳米线具有 p-n-n(+)掺杂分布，具有陡 n-n(+)结，这一点通过扫描电容显微镜得到揭示。通过调制顶部栅极偏置，可以将轻掺杂的 n 段反转至 p(+)，从而形成陡的栅控 p(+)-n(+)结。当反向偏置时，通过静电掺杂的 p(+)-n(+)结会有带带隧穿电流流过。在 375 到 4.2 K 的温度范围内进行的电流-电压测量显示出高温和低温下两种不同的隧穿电流模式，表明存在直接带带隧穿和陷阱辅助隧穿路径。
